My invention relates to roof ventilators for closed vehicles such as buses, trailers, trucks and railway cars, and particularly to an improved closure or lid by which the ventilator opening in the roof of such a vehicle may also serve as an escape hatch for occupants in the vehicle in the event of an accident or other emergency rendering the normal means of egress unusable.
In its more specific aspects my invention provides a lid which in normal operation either closes the roof opening or is raised to a partially elevated position when ventilation of the vehicle so requires, and which can be manually released and forced upwardly to swing fully open in the event of an emergency requiring use of the roof opening as an escape hatch.
I am aware that roof ventilators employing a lid which can be tiled upwardly are well known in the art, including such a lid that can be so tilted in either of two directions for directing air into or exhausting air out the vehicle. U.S. Pat. No. 2,173,890 to Tuttle and U.S. Pat. No. 2,372,164 to Woodhams, for example, show such vehicle roof ventilator panels tiltable upwardly in one direction, and U.S. Pat. No. 2,159,516 to Ball shows one tiltable alternatively for exhaust of air from the vehicle interior by suction or for deflection of air into the vehicle. Also, U.S. Pat. No. 2,517,303 to Green discloses a roof ventilator in which the closure lid may be raised vertically, rather than tilted angularly of the roof opening. The closest prior art to my invention probably is that of U.S. Pat. No. 3,676,954 to Rapport et al. showing a lid for a vehicle roof vent opening which is tiltable upwardly to a venting position by means of worm gear and wheel drive mechanism and which has means for unlatching the housing of the worm mechanism to allow the lid to be swung to a fully open position.